tree ddc6135050fcb792fb4b4b45ee9aadbd050a5526
parent aa711ee3402ad10ffd5b70ce0417fadc9a95cccf
author Alex Elder <elder@inktank.com> 1343226760 -0500
committer Sage Weil <sage@inktank.com> 1343697348 -0700

rbd: encapsulate header validity test

If an rbd image header is read and it doesn't begin with the
expected magic information, a warning is displayed.  This is
a fairly simple test, but it could be extended at some point.
Fix the comparison so it actually looks at the "text" field
rather than the front of the structure.

In any case, encapsulate the validity test in its own function.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>